Page 1 of 2 12 LastLast
Results 1 to 10 of 14

Thread: runout -vs- concentricity

  1. #1
    PC-DMIS demi-Guru
    • Additional Information
      • Years CMM Experience:
      • 7.08333
      • Software Version:
      • 4.2 MR1...Windows XP SP2......24" Monitor :~D
      • Machine Type:
      • B&S Global 15.22.10...TP20...Tesa-M
      • Location:
      • Live in VA..Work in WV..Good Stuff!
      • Job Function:
      • Programmer

    Join Date
    Apr 2006
    Location
    Live in VA..Work in WV..Good Stuff!
    Posts
    1,545

    Question runout -vs- concentricity

    Could anyone give me an easy answer as to the difference between runout and concentricity? Ex. my origin is a circle, I checked another circle. Then, I checked the runout from that dia. to the origin. I got like .0058. Then, I checked the concentricity from that diameter to the origin and got .0035. Any explanation? The print does call for single runout to the origin. Why the big difference? If using runout is the correct way, did I do it right? PLN, (Dat_A), CIR1(Dat_B).....XY origin to Dat_B. Z origin to Dat_A. Then checked the circle at hand. Clicked runout...selected that circle....plugged in my tolerance of .002

    I am using INCHES....FYI

    Thanks!

    Josh
    ~Josh~ Giles Rescue "Ut ceteri vivant"

  2. #2
    PC-DMIS Guru
    • Additional Information
      • Years CMM Experience:
      • Since 1998
      • Software Version:
      • 3.2063 & 3.7
      • Machine Type:
      • B&S (Excel 7-10-7, MicroExcel PFX 4-5-4, One 7-10-7)
      • Location:
      • Southern Tier
      • Job Function:
      • Quality Engineer
    craiger_ny's Avatar
    Join Date
    Apr 2006
    Location
    Southern Tier
    Posts
    2,754

    Default

    Runout > includes form error of the feature being dimensioned (think indicator)
    Concentricity > center to center misloacation of co-axial features (form is not part of the math).

    Craig
    <internet bumper sticker goes here>

  3. #3
    Member
    • Additional Information
      • Years CMM Experience:
      • Since 1987
      • Software Version:
      • 2013 MR1 2013 MR1 offline
      • Machine Type:
      • B &amp; S Global Status
      • Location:
      • St. Louis MO
      • Job Function:
      • Senior Quality Technician

    Join Date
    Mar 2006
    Location
    St. Louis MO
    Posts
    96

    Default

    Concentricity is an axis to axis measurement. Runout is a surface to surface measurement. You could have a rectangular feature with perfect concentricity but horrible runout.


    HTH

    Dennis

  4. #4
    PC-DMIS demi-Guru
    • Additional Information
      • Years CMM Experience:
      • 7.08333
      • Software Version:
      • 4.2 MR1...Windows XP SP2......24&quot; Monitor :~D
      • Machine Type:
      • B&amp;S Global 15.22.10...TP20...Tesa-M
      • Location:
      • Live in VA..Work in WV..Good Stuff!
      • Job Function:
      • Programmer

    Join Date
    Apr 2006
    Location
    Live in VA..Work in WV..Good Stuff!
    Posts
    1,545

    Default

    So....does this look right....The runout of Cir6 to the origin is .0058?

    DAT_A2 =AUTO/CIRCLE,SHOWALLPARAMS = NO,SHOWHITS = NO
    THEO/0,0,0,0,0,1,8.999,0
    ACTL/-0.001,0.0014,0,0,0,1,8.999,0
    TARG/0,0,0,0,0,1
    DCC_ALN2 =ALIGNMENT/START,RECALL:ALN2, LIST= YES
    ALIGNMENT/TRANS,XAXIS,DAT_A2
    ALIGNMENT/TRANS,YAXIS,DAT_A2
    ALIGNMENT/END
    DIM RNOUT3= RUNOUT OF CIRCLE CIR6 TO THE ORIGIN UNITS=IN ,$
    GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH
    AX MEAS NOMINAL +TOL -TOL DEV OUTTOL
    M 0.0058 0.0000 0.0020 0.0000 0.0058 0.0038 -->
    DIM CONCEN1= CONCENTRICITY FROM CIRCLE CIR6 TO THE ORIGIN UNITS=IN ,$
    GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH
    AX MEAS NOMINAL +TOL -TOL DEV OUTTOL
    M 0.0035 0.0000 0.0020 0.0000 0.0035 0.0015 -->
    ~Josh~ Giles Rescue "Ut ceteri vivant"

  5. #5
    Senior Member
    • Additional Information
      • Years CMM Experience:
      • 11
      • Software Version:
      • 3.0864
      • Machine Type:
      • BNS Mistral 07.07.05
      • Location:
      • Milwaukee
      • Job Function:
      • Quality Tech.

    Join Date
    Nov 2006
    Location
    Milwaukee
    Posts
    218

    Default

    Quote Originally Posted by craiger_ny View Post
    Runout > includes form error of the feature being dimensioned (think indicator)
    Concentricity > center to center misloacation of co-axial features (form is not part of the math).

    Craig

    Is this why my runout is showing .004 and a v-block/indicator is showing .00005?

    Has anybody got any documents that supports that this is happening.

    D@mn operators are trying to say the cmm is wrong,,, dirty button pushers.....
    I talk dirty to my cmm. Justn

  6. #6
    PC-DMIS demi-Guru
    • Additional Information
      • Years CMM Experience:
      • 20
      • Software Version:
      • 3.5 MR2
      • Machine Type:
      • Excel 7-10-7, Micro-Val
      • Location:
      • Witness Protection, Ms
      • Job Function:
      • SR CMM Programmer
    bw_bob's Avatar
    Join Date
    Feb 2006
    Location
    Witness Protection, Ms
    Posts
    1,644

    Default

    Quote Originally Posted by justncredible View Post
    Is this why my runout is showing .004 and a v-block/indicator is showing .00005?

    Has anybody got any documents that supports that this is happening.

    D@mn operators are trying to say the cmm is wrong,,, dirty button pushers.....
    The cmm is probably wrong. I check runout with an indicator. To me its the best & most accurate way. My .02
    .....Its called golf because all the other 4 letter words were taken

  7. #7
    PC-DMIS Guru
    • Additional Information
      • Years CMM Experience:
      • Since 1998
      • Software Version:
      • 3.2063 &amp; 3.7
      • Machine Type:
      • B&amp;S (Excel 7-10-7, MicroExcel PFX 4-5-4, One 7-10-7)
      • Location:
      • Southern Tier
      • Job Function:
      • Quality Engineer
    craiger_ny's Avatar
    Join Date
    Apr 2006
    Location
    Southern Tier
    Posts
    2,754

    Default

    ji are you dimensioning two circles? I too do not like the results I get for runout on the CMM but there may be things to consider in light of you getting 0.004 vs 0.00005. First would be the feature vectors. If you are doing 2 2D features such as circle to circle then you absolutely have to be in an alignment scenario that gives them a common vector (when they are measured). If you are leveled to a plane we'll call A and measure circle 1 you need to be in the same level scenario when you measure circle 2 or their vectors will not match and they can show error.

    Knowing that you filter a lot of your outliers I am confident you are getting better form than most so form measuring errors are not much of a susspicion here but should be considered. I am not much of a fan for roundness with a CMM and that carries over to runout.

    Any chance of throwing up some code for the features in question and the dimension.

    My first answer is runout with PCDMIS sucks but I think you should get better than 0.004 when you are getting 0.00005 on the bench.

    Craig
    <internet bumper sticker goes here>

  8. #8
    PC-DMIS demi-Guru
    • Additional Information
      • Years CMM Experience:
      • Since 2000
      • Software Version:
      • V3.2063 &amp; 2010MR1
      • Machine Type:
      • B&amp;S Mistral 07-07-05 &amp; Sheffield Discovery D8
      • Location:
      • Cleveland, Ohio
      • Job Function:
      • CMM Programmer, Auditor, Oversee Inspection Department functions, ASQ-CMI, CQT
    John Kingston's Avatar
    Join Date
    Feb 2006
    Location
    Cleveland, Ohio
    Posts
    2,480

    Default

    Quote Originally Posted by jkb_mcg View Post
    So....does this look right....The runout of Cir6 to the origin is .0058?

    DAT_A2 =AUTO/CIRCLE,SHOWALLPARAMS = NO,SHOWHITS = NO
    THEO/0,0,0,0,0,1,8.999,0
    ACTL/-0.001,0.0014,0,0,0,1,8.999,0
    TARG/0,0,0,0,0,1
    DCC_ALN2 =ALIGNMENT/START,RECALL:ALN2, LIST= YES
    ALIGNMENT/TRANS,XAXIS,DAT_A2
    ALIGNMENT/TRANS,YAXIS,DAT_A2
    ALIGNMENT/END
    DIM RNOUT3= RUNOUT OF CIRCLE CIR6 TO THE ORIGIN UNITS=IN ,$
    GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH
    AX MEAS NOMINAL +TOL -TOL DEV OUTTOL
    M 0.0058 0.0000 0.0020 0.0000 0.0058 0.0038 -->
    DIM CONCEN1= CONCENTRICITY FROM CIRCLE CIR6 TO THE ORIGIN UNITS=IN ,$
    GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH
    AX MEAS NOMINAL +TOL -TOL DEV OUTTOL
    M 0.0035 0.0000 0.0020 0.0000 0.0035 0.0015 -->
    Lots of things to look at here JKB, the location of CIR6 to the ORIGIN would help. Also, roundness of the two diameters. Those together can affect runout. Looking at each individual point would tell us a lot. I'm not saying do that, but it would give more information about the part.
    When in doubt, post code. A second set of eyes might see something you missed.

  9. #9
    Senior Member
    • Additional Information
      • Years CMM Experience:
      • 11
      • Software Version:
      • 3.0864
      • Machine Type:
      • BNS Mistral 07.07.05
      • Location:
      • Milwaukee
      • Job Function:
      • Quality Tech.

    Join Date
    Nov 2006
    Location
    Milwaukee
    Posts
    218

    Default

    SCN-B- =BASICSCAN/CYLINDER,SHOWHITS=NO,SHOWALLPARAMS=YES
    0,0,0.125,CutVec=0,0,1,OUT
    InitVec=1,0,0,DIAM=0.507,ANG=1440,PITCH=0.1,DEPTH= 0,THICKNESS=0,PROBECOMP=YES,AUTO MOVE=NO,DISTANCE=0
    FILTER/DISTANCE,0.1
    EXEC MODE=FEATURE,USEHSSDAT=YES,USEDELAYPNTS=NO
    BOUNDARY/
    HITTYPE/VECTOR
    NOMS MODE=MASTER
    ENDSCAN
    MOVE/CLEARPLANE
    SCN064 =BASICSCAN/CIRCLE,SHOWHITS=NO,SHOWALLPARAMS=YES
    0,0,-0.3,CutVec=0,0,1,OUT
    InitVec=1,0,0,DIAM=2.15395,ANG=360,DEPTH=0,THICKNE SS=0,PROBECOMP=YES,AUTO MOVE=NO,DISTANCE=0
    FILTER/DISTANCE,0.1
    EXEC MODE=FEATURE,USEHSSDAT=YES,USEDELAYPNTS=NO
    BOUNDARY/
    HITTYPE/VECTOR
    NOMS MODE=MASTER
    ENDSCAN
    MOVE/CLEARPLANE
    CYL-B- =FEAT/CYLINDER,RECT,OUT,LEAST_SQR
    THEO/0,0,0.32233,0,0,1,0.507,0.39466
    ACTL/-0.00009,0.00003,0.32538,0.0008414,-0.0005587,0.9999995,0.50672,0.39823
    CONSTR/CYLINDER,BF,SCN-B-,,
    MOVE/POINT,NORMAL,2.90782,6.74994,8.84181

    Due to the wide open tols, I did not filter the scan cyl to create the cyl-b-.
    I did increase the scan on the cyl, from .4 pitch to .1 and the rotation is at 1440, which means I make 4 complete revs around the axis of the cyl, each .1 apart at the end, like a screw. The 2nd is just one scan since the tols .00195...
    I talk dirty to my cmm. Justn

  10. #10
    Ultra Senior Member
    • Additional Information
      • Years CMM Experience:
      • too many
      • Software Version:
      • 2011 MR1
      • Machine Type:
      • BnS, Dea, Optiv, Tesa
      • Location:
      • Madison, Alabama
      • Job Function:
      • Director of Quality

    Join Date
    Feb 2006
    Location
    Madison, Alabama
    Posts
    767

    Default

    JKB,
    If your drawing is speaking ASME:
    Runout is a composite tolerance. Runout is a SURFACE control (to a datum axis). It will control surfaces constructed around a datum axis, and those constructed at right angles to a datum axis. It will control form, orientation and location of features. Using "total runout" to a surface around a datum axis will control circularity, straightness, coaxiality, angularity, taper, and profile of that surface. Pretty powerful huh?

    Concentricity:
    Is a condition where the median points of ALL diametrically opposed elements are congruent with the axis (or center point) of a datum feature. You'd be inspecting a point cloud - so to speak.

    Pcdmis is going to treat concentricity and coaxiality the same way. This is wrong. Your concentricity results will be based the same way a position formula is. For runout, (and I would have to explore this) I believe pcdmis would be taking your larger and smaller inspection points - and reporting the difference between them. That is why you would be having the discrepency.
    I would exercise extreme caution when inspecting runout on a cmm.

    A side note:
    ISO and ASME differ on concentricity definitions. our "coaxiality" (asme) is there concentricity (ISO). This just 1 of the many differences betwen them.

    Kev
    RFS Means Really Fussy Stuff

    When all you have is a hammer - everything looks like a nail....

Similar Threads

  1. Circ. Runout on 4.2
    By skinnyhips in forum PC-DMIS for CMMs
    Replies: 2
    Last Post: 11-29-2007, 03:36 PM
  2. Total Runout with MMC?
    By Underspec in forum PC-DMIS for CMMs
    Replies: 10
    Last Post: 10-31-2007, 08:45 PM
  3. Total Runout
    By John Kingston in forum PC-DMIS for CMMs
    Replies: 2
    Last Post: 05-30-2007, 09:22 AM
  4. RUNOUT vs CIRCULAR RUNOUT
    By VONDY in forum PC-DMIS for CMMs
    Replies: 3
    Last Post: 10-04-2006, 03:25 PM
  5. Runout
    By Jay Gus in forum PC-DMIS for CMMs
    Replies: 0
    Last Post: 08-22-2006, 03:58 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •